Precision Control of Piezoelectric Actuator Using Modified Bouc-Wen Model

Piezoelectric actuators (PEAs) are finding broad acceptance in applications where precision motion (sub-nanometer level), large actuated force and/or high frequency operation are required. However, PEA also exhibits an undesired hysteresis phenomenon which is nonsmooth nonlinearity. Because of the unknown hysteresis, the performance of PEA is limited especially in speed and accuracy. Therefore, there is a need for an approach to model and control in order to eliminate the hysteresis effects. In this paper, a new modified Bouc-Wen (MBW) model is proposed. Then, we try to fuse the MBW with a model adaptive control technique to control a PEA. The adaptive controller guarantees the stability of the closed-loop control system. Finally, the experimental results demonstrate that the proposed method effectively linearizes the hysteresis nonlinearity and improves the trajectory tracking compare to conventional control method.